Fuse-plug



T. C. VB0TH A. H. TRU-MULL AND R7. A. SC-HOENBLEHG. FUSE PLUG. APPLICATION man 'MAR.20,`191*6.

1,335 .362. patentd Mar, so, 1920.

y' UNITED sTATEs Aiijiifrl OFFICE.

ToNJEs A.A c. :BOTH AND ALEXANDER i-I.- TRUMBULL, or srnArronii, CONNECTICUT, AND RALPH A. SCHOENBERG, 0F NEW YORK, N. Y., Assienoias 'ro THE-CONNECTICUT ELECTRIC MFG. C0., OF BRIDGEPORT, CONNECTICUT, A CORPORATION CUT.

y FUSE-PLUG.

rl`he chief objects of our invention are to improve the eiiiciency and construction of fuse plugs. With these objects in view one feature of our invention consists in a pilot or lead o'n the shell at that end of the plug which enters the receptacle, this portion in they form shown being unthreaded 'and of substantially less diameter than thediaineter of the threaded portion. One great advantage of this feature is that in starting the plug into its receptacle a lead is provided to hold thel plug in position so as to thread it into the receptacle and the plug starts at once to screw into place whereas heretofore if the threads are not in alinement and the plug is tipped a little the plug will not screw into the receptacle. This is bad because as a rule the receptacles fo'i` fuses are somewhat inaccessible and difficult to reach to renew fuses and'on account of the position of the user the latter will easily tip the fuse plug so that it will not enter the receptacle or cutout readily. V'Vith our invention, however, it is practically impossible to tip the plug to such an extent as to prevent immediate threaded engagement on turning of the plug. Another great advantage of this feature of our fuse `is that for a given size plug there are required less turns of the plug to put it fully into the receptacle and this is of particularly important advantage in cases where the receptacles are somewhat inaccessible because the user will have less rotation to effect.

4This pilot or lead feature is particularly advantageous in fuse plugs in which the lining for the screw shell is of non-brittle material such as liber butit is also highly useful in fuse plugs of other types.

Another'feature of our-invention consists in a substantial and positive barrier located in the direct line between the centerV Contact and the point of connection of the fuse wire and shell. In` the preferred forni this par- Specification of Letters Patent. I Patented Mail. 30, 192C.A v.Application led March 20, 1916. Serial No. 85,25. i

tition extends crosswise. of the plug. The object of this feature is to prevent the holding of an arc on 'blowing of the fuse which are islikely to burn 'the shelland cause other damage.

. Another feature f our invention is a back ground near the fuse wire so that one may easily tell whether or not the fuse has blown, f

A'it' being a 'fact that when a fuse blows it usually blackens or chars the covering so that heretofore ithas been dilicult to see intothe fuse plug suiiiciently well to determine accurately whether the fuse has blown or not.V In. the preferred form lthe background is of a color contrasting with the color of the fuse wire. l y

AAnother feature of our invention is a par- 'tition which divides the interior of the fuse a arranged so that the escaping gases will not come in contact with any metal parts in passing out of the plug and thereby avoiding melting oi' burning of such parts and avoiding flame outside of the fuse plug.

Another feature of our invention is an outside washer which resembles a valve in its action.` The purpose of this is to pro-v vide a' damper to prevent the escape of gas in the form of a flame. Very slight air space is provid-ed between this washer and the adjacent member and the washer is made thin so that if the pressure is great the washer will give tol make a larger passageway.

Other features will be pointed out below.

In the drawings:

Figure l is a central vertical section of a fuse plug embodying our invention;

Fig. 2 is a section on line 2--2 of Fig. 1, looking in thedirection of the arrows;

Fig. 3 is an elevation, partly in vertical section, of a modification;

F ig. 4 is a top plan of the inner washer;

Fig.Y 5 is a top plan of the outer washer;

Fig. 6 is a top plan of the intermediate washer;

Fig. 7 is a bottom plan of the same;

Fig. .8 is a perspective view of the upper lining member;

0F CONNECTI- than. the threaded 9 is aperspective view of the interposed member Fig. 10 is a perspective viewof thelovver lining member; and

Fig. 11 is \a plan of the modified interposed member.

.' Shell -A has an upper'outturned 'ange a.,

a threaded portion, an unthreaded pilot or lead portion al'of substantially less diameter portion and an inturned flange a2, the latter having a central opening a3 and openings a4 in the. form of perforations andother openings in th'e form of notches a5. i V l A tubular insulating lin-ing of fiber is pro vided consisting of lower member .B and upper member B1 and held in place between these members is an interposed member B2 1iaving a passage or opening b2, this member B2 acting as a partition extending across the interior of the plug and dividing the-latter into twochambers, the opening b2 providing an outlet for gases other. l

The fuse wire D is electrically connected at oneiend -to the shell and at the other end is connected by 'solder d to center contact E, the fuse being bent as shown and passing through opening b and in'this way a substantial and positive Ybarrier is `formed.

against the holding of an arc, the member B2 being a barrier interposed into the direct path extending from the point of connection of the vfuse and shell tothe point of connection of the fuse and centercontact.

Fitting tightly within member B is fiber washer F having depressions' f, each provided with a perforation f1 forming a gas outlet,l and having upwardly extending indentations f2 and having a central aperture l y -Intermed1atefiber washer G 1s outside of,

but adjacent to, the flange a2 of theshell" and has central aperture g, openings g1 and upwardly extending indentations g2.

Outer fiber washer H `has a central aperture h and upwardlyextending "indentations 71,1. i. The'three washers F, Gr and H are clamped together and to the flange@2 of the shell by means of the head e and c lenched'portions el e1 of the center contact, the body of which passes through apertures f3, gand t. When so clamped the depressions f are in engagement with the notches a5 to'prevent relative rotation of the parts, indentations -g2 pass' through openmgs ai* and enter indentations f2 thus further preventing relative rotation of the parts and indentations 71,? enter indentation's g2 from thebottom, thus further preventing relative rotation of the parts.

Washer H is relatively very thin and is preferably slightly spaced from washer G so 'that when gas escapes through perforations f1 and openings g1 it will escape be:

'pressure is'very great the washer H from each chamber to the tween washers 'G and H, the latter regulating the flow of gas, it being clear that if the will yield sufficiently to allow proper vent. 'It will be observed that the lower face of depression f bears against the adjacent corner of opening g1 and the more pressureV of gas Athere is the tighter is the joint.

The outlet through perforation f1- and opening g1 is an. insulated onewhich has the very important advantage of avoiding melting or burningmetal parts and preventing 4flame outside the plug.l

Exterior liber insulation K is provided for a portion of the shell and is seated between flange t and ledge a on the shell, this 'insulation having an extension 7c.

A transparent cover L of mica rests on flange a.' 'A metal ring M perforated at in Iand flanged at m1 clamps the cover` and extension 7c together and forms va. hand hold, the extension /c act-, ingas insulation therefor. y

InAFig. 3 we show another form of partition and barr1er B3 which has perforation A 713 and is elliptical in form and in this case the tubular lining Bfis in one piece and this construction is desirable for some purposes.

Members B2 and B? are close to the respective fuse ywires D and D1 and therefore furnish an excellent and convenient back-l `O'round so that the user can rea' ily determme whether the fuse has blown or not. We prefer to have the members B2 and B3 of a color contrasting with the color of the --fus'e in order to increase the eifectiveness of the background and We'have found white fiber a very effective material of which members turned flange on one end thereof with an unthreaded lead portion adjacent to said flange and extending part way up said shell; a plurality` of insulating members heldin adjacency to said flange; and a center contact attached to said end of the body member by said insulating members. -v

3. A fuse plug comprising a screw shell body .memberl having an unthreaded lead portion; an insulating lining for said shell; a chamber in said body member; a center contact member; a fuse in said chamber connected -to said members; insulation between said lshell 4and center contact members; and means in said chamber interposed in the direct line between the points of connection of said fuse with saidmembers; to intercept the direct path of an arcl from one or said points to the other; an indirect gas outlet from said chamber; a hand hold;

and exterior insulation for a portion of saidA portion Qn one end thereof and a liange at the other end; an exterior insulation below said flange; a cap for said shell; a metallic hand and 'cap holding means, said means being insulated from said flange and shell by said exterior insulation.

6. A fuse plug comprising a screw shellbodymember; a tubular insulating` lining for said member; v a chamber within said lining; awcover for said chamber; metallic means to attach said cover, said means beinginsulated from the shell body'member; a center contact member; an insulating support for attaching said contact member to said shell body member; a fuse connecting said members; and a separate member within the body interposed in the direct line of connection ofsaid fuse and said shell and center contact member.

7. A fuse plug comprising a screw shellbody member; a tubular 'insulating lining for said member; a center contact member and an insulating support for attaching said center contact member to one end of said shell body member; a fuse connecting said members; means within the.b0dy membei' interposed in the direct line between the points of connection of said fuse and said members to intercept the direct path of an arc from one of said points to the other; a cover for the other end of' the plug; and metallic means insulated from the conducting members to connect said cover to said plug.

8, A fuse plug comprising a shell contact member; a center contact member; a chamber; a fuse in said chamber; and means interposed between the points of connection of said fuse to intercept the direct path of an arc from one of said points to the other; a gas outlet from said chamber; and means to regulate said outlet for gases formed when said fuse blows.

9. In a fuse plug the combination of av plurality of contacts; an insulating chamber; a fuse in said chamber; and a gas out* let through one 0f the contacts, one of the vwalls of said chamber having a perforation corresponding with said outlet and an insulation for said outlet.

10. A fuse comprisingI a side contact; a centercontact; a chamber; a fuse in said chamber; said fuse connecting said contacts; an outlet for gas through one of said conforming tacts; and means to insulate said outlet.

11u-A fuse plug comprising a shell contact; a center Contact; a fuse; a chamber andan outlet for gasesthrough, said shell contact and means to insulate said outlet and said shell and center contact.

12. InA combination a shell with an inturned flange provided with an opening;

a center cont-act; a washer insulating said shell and center contact and provided with a projection to engage said opening to prevent relative rotation4 o f the shell. and,

washer.

18. A fuse plug comprising a shell with au inturned flange provided with an opening; a center contact; a washer insulatingl said shell and center contact and provided with a projection to engage saidA opening to prevent relative rotation of the shell and washer, said projection being provided with a gas outlet.

14. A fuse plug .comprising a shell with' an inturned ange provided with `two openings; a center contact; a washer linside the plug insulating said shell and center contact and Vprovided with a projection to eugage one of said openings 4to prevent relative rotation of the washer and shell, said projection being provided with agas outlet; a second washer outside the shell and.

pi'ovidedwith a protuberance to engage the other of said openings in the shell and also provided with a perforation to receive the projection of the tirstwasher. 1 5. A fuse plug comprising a side contact; a fuse chamber; a center contact at the bottom ot' said chamber; said contacts; insulating materialsupporting` said center contact; an outlet for gas through said insulating material; and ...a washer covering said outlet to receive the flash of an arc or Vhot gas blowing out through said outlet. .f

16. A fuse plug comprising a shell; a center contact; a fuse; a chamber; an insulating support for the center contact; said support having a gas outlet; a yieldablc member on one side of said support and coverii'ig said outlet; said outlet to 4be regulated by the pressure of gas in said chan1 'ber acting upon said yieldable member when the fuse blows. I

17. A fuse plugv comprising a shell; a chamber; a fuse; a center contact; an insulating support for said contact; a gas outlet through said support; a yieldable member on one side of said support and covering said outlet; said outlet to be regulated a fuse connecting the pressure of gas in said chamber actin'g upon the yield le member. on the blowino* ofsaid fuse; saidsupport and member .being provided with coperating portions.

to prevent relative rotation between them.

18. A fuse plugcomprising a shell body member; a tubular lining therefor; a center contact; and insulation between said shell and contact comprising washers, one ot which vfits within said tubular lining.

19. A fuse plug comprising a chamber;

a lfuse; a gas outlet; and means outs-ide of said chamber `to regulate4 said outlet when Ia center contact;

an inturned flange provided with openlnggys;`

washers insulating said shell and contact and'provided withproj ections tQ enga'ge said openings toprevent .relative rotation between saidwashers and the shell and center contact, 'said washers 'bein provided with a gas outlet; means to regu ate said outlet; a fuse connected to the vvshell and center contact; a member interposed in the direct line between the points ofconnection of 4the usewithv the shell and center 'contact 'exterior insulation for said shell; and a hand hold.

22. A'fuse plug comprising a screw shell body member; lan insulating lining for said vmember; a center contact member; a fuse conneetin `said members; and. a member separate rom said lining 'to intercept thedirect path of an arc from one of the points of connection of said fuse to the other; a gas outlet; 'lmeans to .insulate said outlet; admeans to regulate said outlet when the fuse blows.

' cover;

23. A fuse plug comprising a screw shell body member; a center contact; a fuse; interior insulation; means to intercept the di rect path of an arc caused by said 'fusepa -means to attach said cover-, said means being 4insulated from the conducting member; exterior insulation Jfor said body member; a'gas outlet from Asaid body -memjber; and means to regulate said outlet for 'gases formed when said fuse blows.-

24.A fuse plug comprising a shell; van

insulating lining thereforv comprlsing two pieces;pand a member extending crosswise 4of the plug and held in place by said two "picces.

25. A fuse plug comprising a screw shell body member; tubular lining therefor; a center contact at one end of said member; a

closure for that end of the plug; a cover for the other end of the saidplug and forrn ing a chamber; a member extending crosswise of the chamber and dividingthe `1nterlorfthereofmto two sectlons; a fuse consaid shell; means to attach means being insulated `from fuse blows and said washer and said mem/her nected to saidshell; exterior insulation for a metallic han-d and cover holding means; r'said metallic the conducting members. f

26. A fuse plug comprising a shell con-y tact; a chamber; a center contact.; al fuse;

a gas outletl at the Acenter contact end of the plug; and means to regulate the flow of gas y lated by the pressure of gas within said throughsaid outlet,- said'means beingreguchamber'when the fuse blows. l

27. A fuse plug comprisinga shell; a center contact; and a plurality of washers to insulate the shell and center contact; said vwashers having portions coperatmg to prevent relative rotation between them.

' 28. A fuse plug comprisingI a lshell; a center contact; a chamber; a fuse in said chamber; a washer .insulating the shell from the center contact andprovided with a gas outlet; and a member to regulate said .out-VA let, said outlet-being regulated by gas pressure from within said lchamber when the having portions coperating tive rotation between them. v

29. In a` fuse the combination ofafplurality of contacts; a chamber; a fuse in said chamber; an outlet'for gas through `ome of said contacts; means to insulate said outlet; and means to regulate said `outlet when the fuse blows'.v

30. In a fuse the combination of' a plurality'of contacts; a chamber; afuse in said chamber an outlet for gas from said cha'mber; and means outside of said chambery to regulate said outlet. A

31. A -fuse plug comprising a side contact; a fixed center contact, a chamber;- a fuse; in said chamber; a gas outlet from said chamber; and means to regulate said outlet, `said tol prevent ily/ela- 'means being regulated by the pressure of gases within said chamber when .a fuse blows. y l

32. In a fuse the combination of a plurality-of contacts; a chamber; a fuse in said chamber; a gas outlet from said chamber, and means located outside said chamber and acting by gas pressure when a fuseblows to'` regulate said outlet.

f 33. In a fuse the combination ofya cham-y ber; a plurality of fixed contacts; a fuse. electrically vconnected to said'contacts; a gas outlet; and means to regulate said outlet. 434. In a fusefthe combination 'of a plurality of contacts; a chamber; a fuse in said chambertjand directly 'connected with said contacts; a gas outlet from said chamber; and4 means to regulate said, outlet, said.

ion

means being controlled by the gas pressure in said chamber when a fuse blows.

35. In a fuse the combination of a plurality of contacts; a chamber; a fuse in said chamber; a gas' outlet from-said chamber;

and means independent of said contacts to taets, each having a portion exposed-exterregulate said outlet. 'nally ofthe device; a chamber; a fuse in said 10 36. An insulating lining for a fusev plug chamberconnectng said fXed contacts; a'gas having a screw shell body member, said lin- 'outlet from said chamber; and means to 5 ing comprising a partition piece with a fuse .regulate said outlet When the fuse blows.

passage therein and tubular portionsX eX- TONJES A. C. BOTH. tending each side of said partition piece. ALEXANDER AH. 'TRUMBULL 37. A fuse plug comprising two fixed eony RALPH A. ASCHOENBERG. 

